Myocardial bridging as a cause of acute myocardial infarction: a case report

Myocardial Bridging in Patients Undergoing Coronary Angiography for Coronary Artery Disease

Introduction Myocardial bridge is a rare, benign, normal anatomical variant of the coronary artery that puts the patient at risk for significant cardiac symptoms, resulting in myocardial ischemia, arrhythmia, and sudden cardiac death. The aim of the study was to assess the prevalence and characteristics of myocardial bridging (MB) in patients with chest pain undergoing coronary angiography. Methodology A total of 1301 patients presenting with chest pain suggestive of acute coronary syndrome with associated non-invasive supportive cardiac evaluation were subjected to coronary angiography by Philips Allura Xper FD10 Cath Lab (Philips Healthcare, Andover, MA) and evaluated. Results Out of 1301 patients, the mean age was 54.70 ± 11.41 years with a male-to-female ratio of 1.9:1. Tobacco use and diabetes mellitus were the most common associated risk factors (49% and 44%, respectively). MB was seen in 51 patients, making the prevalence 3.9%, with male predominance over females in the ratio of 3.9:1. The most common clinical presentation was unstable angina (UA) (n = 22, 43.1%), followed by stable angina (SA) (n = 11, 21.6%), non-ST-elevation myocardial infarction (NSTEMI) (n = 10, 19.6%), and ST-elevation myocardial infarction (STEMI) (n = 8, 15.7%). Myocardial bridges were more common among patients with stable coronary artery disease. The left anterior descending artery (n = 51, 3.9%) was involved in all the cases and the middle segment was affected in all patients with MB. Among patients with myocardial bridge, 26 patients (51%) had atherosclerosis and 25 patients had a normal artery. Among patients with myocardial bridge with atherosclerosis, 17 patients (65%) had atherosclerosis in the same artery in which the myocardial bridge was present. Among patients with myocardial bridge with atherosclerosis, nine patients (52%) had atherosclerosis proximal to the bridge, three patients (17%) had atherosclerosis distal to the bridge, and five patients (31%) had atherosclerosis both proximal and distal to the bridge. Conclusion The prevalence of MB in the Indian population is significantly lower than in the Western populations, and it is significantly higher in the male population with patients diagnosed as normal coronaries on coronary angiography.

Acute Myocardial Infarction Due to Myocardial Bridge Treated With Surgery: a Case Report

Myocardial bridging is congenital anomaly characterized by segment of epicardial coronary arteries passing through the myocardium. Various ischemic conditions are related with this pathology. We report a case of myocardial bridging that was complicated with acute anterior myocardial infarction and a review of the literature. The patient was treated successfully with coronary bypass graft surgery after unsuccessful percutaneous intervention.

Myocardial Bridging: Two Different Clinical Presentations in Young Males Involving Left Anterior Descending Coronary Artery

Myocardial bridging is a rare anatomical variant that can lead to detrimental cardiac consequences when undiagnosed and untreated. This rare variant can induce anginal-type symptoms due to disrupted blood flow to the myocardium during systole. The patients presented in this report of two cases had previously undiagnosed myocardial bridging of the left anterior descending artery, however clinically, they presented quite differently. Here we present two cases discussing the course of diagnosis and treatment of myocardial bridging of these two patients. The goal of this case report is to highlight the significant cardiovascular injuries that can be a result of undiagnosed myocardial bridging.

Plaque herniation after stenting the culprit lesion with myocardial bridging in ST elevation myocardial infarction: A case report

BACKGROUND

Myocardial bridging (MB) is increasingly recognized to stimulate atherogenesis, which may contribute to an acute coronary syndrome. Stenting the coronary segment with MB has been recognized to have an increased risk of in-stent restenosis, stent fracture and coronary perforation. The safety and efficacy of stenting the culprit lesion with overlaying MB in ST elevation myocardial infarction (STEMI) as primary reperfusion therapy has not been established.

CASE SUMMARY

We reported a patient who presented with inferior STEMI with a culprit lesion of an acute thrombotic occlusion in the right coronary artery and thrombolysis and thrombin inhibition in myocardial infarction 0 flow. After the stent placement during primary percutaneous coronary intervention, intravascular ultrasound revealed MB overlying the stented segment where heavy atherosclerotic plaque were present. Likely due to the combination of plaque herniation or prolapse caused by MB, as well as local increased inflammation and thrombogenicity, acute stent thrombosis occurred at this region, which led to acute stent failure. The patient required an emergent repeated cardiac catheterization and placing a second layer of stent to enhance the radial strength and reduce the inter-strut space.

CONCLUSION

Plaque herniation or prolapse after stenting a MB segment in STEMI is a potential etiology for acute stent failure.

What is the optimal treatment for symptomatic patients with isolated coronary myocardial bridge? A systematic review and pooled analysis

BACKGROUND

Myocardial bridging is a common coronary anomaly, with few severe adverse events but a relevant symptom burden. Myocardial bridging treatment, however, remains uncertain because of the lack of randomized trials.

MATERIAL

MEDLINE/PubMed was systematically screened for studies reporting on isolated myocardial bridging diagnosed at coronary angiography or with coronary computed tomography in patients admitted for suspected angina or with an acute coronary syndrome. Baseline, treatment and outcome data were appraised and pooled according to treatment (medical therapy, bypass surgery/myotomy or stenting).

RESULTS

A total of 899 patients in 18 studies were included with a low prevalence of traditional risk factors, especially diabetes (15.6%, interquartile range 2.5-21.5). After a median of 31.0 months (interquartile range 12.4-37.1), major cardiovascular events (composite of death, myocardial infarction or target vessel revascularization) occurred in only 3.4% of the study patients and 78.7% [70.5-86.9; 95% confidence intervals (CI)] were managed conservatively and free of symptoms. When an invasive strategy was planned, freedom from angina was higher in patients treated with surgery [84.5% (78.4-90.7; 95% CI)] than in those treated with stenting [54.7% (38.9-70.6; 95% CI)]. Patients in the stenting group experienced a high incidence of major cardiovascular events related to target vessel revascularization [40.07% (19.83-60.32; 95% CI)]. Meta-regression showed that patients treated with beta-blockers or with a history of hypertension were more likely to remain free from angina (B -0.6, P = 0.013; B -0.66, P = 0.006).

CONCLUSION

Patients with symptomatic isolated myocardial bridging generally have a good long-term prognosis. Pharmacological treatment alone, especially with beta-blockers, is able to improve angina in most cases. Surgical treatment appears to be more effective than stenting in nonresponders.

Assessment of Myocardial Bridge by Cardiac CT: Intracoronary Transluminal Attenuation Gradient Derived from Diastolic Phase Predicts Systolic Compression

Objective

To study the predictive value of transluminal attenuation gradient (TAG) derived from diastolic phase of coronary computed tomography angiography (CCTA) for identifying systolic compression of myocardial bridge (MB).

Materials and Methods

Consecutive patients diagnosed with MB based on CCTA findings and without obstructive coronary artery disease were retrospectively enrolled. In total, 143 patients with 144 MBs were included in the study. Patients were classified into three groups: without systolic compression, with systolic compression < 50%, and with systolic compression ≥ 50%. TAG was defined as the linear regression coefficient between intraluminal attenuation in Hounsfield units (HU) and length from the vessel ostium. Other indices such as the length and depth of the MB were also recorded.

Results

TAG was the lowest in MB patients with systolic compression ≥ 50% (-19.9 ± 8.7 HU/10 mm). Receiver operating characteristic curve analysis was performed to determine the optimal cutoff values for identifying systolic compression ≥ 50%. The result indicated an optimal cutoff value of TAG as -18.8 HU/10 mm (area under curve = 0.778, p < 0.001), which yielded higher sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy (54.1, 80.5, 72.8, and 75.0%, respectively). In addition, the TAG of MB with diastolic compression was significantly lower than the TAG of MB without diastolic compression (-21.4 ± 4.8 HU/10 mm vs. -12.7 ± 8 HU/10 mm, p < 0.001).

Conclusion

TAG was a better predictor of MB with systolic compression ≥ 50%, compared to the length or depth of the MB. The TAG of MB with persistent diastolic compression was significantly lower than the TAG without diastolic compression.

Myocardial Bridging

Myocardial bridging is rare. Myocardial bridges are most commonly localized in the middle segment of the left anterior descending coronary artery. The anatomic features of the bridges vary significantly. Alterations of the endothelial morphology and the vasoactive agents impact on the progression of atherosclerosis of myocardial bridging. Patients may present with chest pain, myocardial infarction, arrhythmia and even sudden death. Patients who respond poorly to the medical treatment with β-blockers warrant a surgical intervention. Myotomy is a preferred surgical procedure for the symptomatic patients. Coronary stent deployment has been in limited use due to the unsatisfactory long-term results.

Evaluation of left ventricular function by three-dimensional speckle-tracking echocardiography in patients with myocardial bridging of the left anterior descending coronary artery

BACKGROUND

To understand the influence of myocardial bridging (MB) on left ventricular (LV) function, myocardial function was studied in patients with MB of the left anterior descending coronary artery (LAD) using three-dimensional speckle-tracking echocardiography (STE).

METHODS

Left anterior descending coronary artery MB was diagnosed by coronary angiography in 82 subjects. Patients were divided into three groups according to the percentage of systolic narrowing of the compressed segment: 30% to 49% was defined as group I (24 patients), 50% to 74% as group II (28 patients), and ≥75% as group III (30 patients). Thirty gender- and age-matched normal subjects were included as controls. Left ventricular myocardial deformation was estimated by three-dimensional STE.

RESULTS

Left ventricular ejection fractions were normal in all patients, but diastolic function was impaired in groups II and III (E/E' ratio, 9 ± 3 and 10 ± 3, respectively). The amplitudes of longitudinal strain (LS) and area strain (AS) of the LAD territory was significantly reduced in groups II and III compared with controls and group I (LS, -15 ± 2% and -12 ± 1% vs -19 ± 2% and -18 ± 2%; AS, -22 ± 2% and -13 ± 2% vs -33 ± 4% and -33 ± 3%; P < .0001), but the amplitudes of circumferential and radial strain showed no intergroup differences. Longitudinal strain and AS were significantly lower in patients with fractional flow reserve < 0.75 than in those with fractional flow reserve ≥ 0.75 (P < .0001), with relative preservation of circumferential and radial strain. The severity of LAD compression was significantly associated with AS and LS of the LAD territory (r = -0.92 and r = -0.84, respectively, P < .0001), but the correlations with circumferential and radial strain were modest (r = -0.36 and r = -0.32, respectively, P < .05).

CONCLUSIONS

With the increasing severity of systolic compression of the mural coronary artery, LV diastolic function and regional systolic deformation (AS and LS) of the MB perfusion territory were reduced. Three-dimensional STE can detect subtle myocardial dysfunction in patients with MB.

Cardiogenic shock accompanied by dynamic left ventricular outflow tract obstruction and myocardial bridging after transient complete atrioventricular block mimicking ST-elevation myocardial infarction: a case report

Background

Dynamic left ventricular outflow tract obstruction with or without mitral regurgitation is typically observed in hypertrophic cardiomyopathy, but is also occasionally seen without left ventricular hypertrophy. In this report, we present a case of cardiogenic shock that mimics ST-elevation myocardial infarction, due to dynamic left ventricular outflow tract obstruction with transient mitral regurgitation and myocardial bridging after transient complete atrioventricular block.

Case presentation

A 65-year-old man with hypertension presented himself at the emergency department with syncope after chest pain. His initial electrocardiography showed inferior ST elevation with profound precordial ST depression and transient complete atrioventricular block. Due to sustained hypotension, an intra-aortic balloon pump was applied. His coronary angiography revealed almost normal right coronary artery and left circumflex artery and only a severe myocardial bridge in the mid-segment of his left anterior descending artery. Instead, severe mitral regurgitation was found without regional wall motion abnormality both in the left ventriculography and the portable echocardiography. However the severe mitral regurgitation completely disappeared in follow up echocardiography the day after. The pressure gradient across the left ventricular outflow tract was measured at 8.95 mmHg during the resting state, and was increased to 38.95 mmHg during the Valsalva state.

Conclusions

The patient presented with a case of cardiogenic shock that mimicked ST-elevation myocardial infarction due to dynamic left ventricular outflow tract obstruction combined with myocardial bridging in the mid-left anterior descending artery.

Atherosclerosis and myocardial bridging: Not a benign combination. An autopsy case report

Myocardial bridging is a congenital coronary anomaly with a variety of clinical manifestations. Traditionally, myocardial bridging has been considered a benign condition, but some cases of myocardial ischemia, infarction and sudden cardiac death due to myocardial bridging have been reported. Various studies have suggested that in their intramyocardial segments, these vessels are protected from obstructive atherosclerosis, with atherosclerosis being present in the proximal part of the artery. We report a case in a 45-year-old male who had a 2.5-cm long myocardial bridging over the left anterior descending artery, with obstructive atherosclerosis being present in the proximal as well as the intramyocardial part (part of the artery below the myocardial bridge). Atherosclerosis occurring in the intramyocardial segment is a rare occurrence, and combined with systolic narrowing by the myocardial bridge can lead to ischemia of the cardiac musculature.

Myocardial bridges: A review

Much has been written regarding the potential clinical significance of myocardial bridges. As such bridging is often seen in normal individuals, it is clear that not all arteries bridged by myocardial segments produce clinical symptoms thereby suggesting that this feature may simply be an anatomical variant. However, some authors who have considered these bridges as the cause of cardiac ischemia have suggested two potential mechanisms for their pathophysiology. The first is a phasic systolic compression of the bridged segment with persistent mid-to-late diastolic reduction in arterial diameter and the second proposes a reduction in arterial flow. Both mechanisms may contribute to a reduced reserve in coronary blood flow. In this review, we discuss the evidence that exists regarding myocardial bridging and the potential for bridging to cause myocardial ischemia.

Unexpected death of a young woman: is myocardial bridging significant?--A case report and review of literature

Myocardial bridging (MB) refers to a congenital condition where a segment of a major coronary artery courses within the myocardium for a variable distance, and has been reported as an incidental finding in many cases. However, in some situations it has been shown to be associated with acute coronary syndromes, arrhythmias, myocardial ischemia and sudden death. We present the case of a 26-year-old Chinese woman with no previous history of disease who died unexpectedly in hospital. She had a 'common cold' with its associated symptoms. Autopsy revealed the presence of MB of the left anterior descending artery and microscopic examination showed associated cardiac lesions such as contraction band necrosis and interstitial fibrosis in the region supplied by the embedded artery. The coronaries were otherwise patent. Gross and microscopic examination of other organs was unremarkable. Toxicological analysis of body fluids and stomach content excluded death due to either drug intoxication or known poisonous substances. MB could have been responsible for death, but the disparate attitudes towards this phenomenon made this assumption open to discussion. We provide the case description and a short review of the literature on fatal and near- fatal cases involving MB.

Heart pump system in "heart-mural coronary artery-myocardial bridge" simulative device

The myocardial tissue covering the artery is termed a myocardial bridge. But so far many researches on the myocardial bridge have been involved with clinical patients or animals, which have some limitations (e.g. lack of systematicness, difficulties in measuring the flow in the mural coronary artery and so on). Designing a "Heart-Mural coronary artery-Myocardial Bridge" Simulative Device provides a good approach to solve above problems; however, documents on this subject have seldom been reported until now. The heart pump as the key part of the whole simulative device should be able to simulate the waveform of blood pressure, adjust blood flow and regulate heart rate. Our experimental results basically met above requirements. The heart pump proposed in the paper presented an alternative experimental method to go further into other issues about the cardiovascular circulation system.

"Mushroom cloud": a giant left ventricular pseudoaneurysm after a myocardial infarction due to myocardial bridging--a case report

Left ventricular pseudoaneurysm is an uncommon complication after transmural myocardial infarction, occurring when a free wall rupture is contained by adhesions of the overlying pericardium preventing acute tamponade. In this report, an unusual case of a 61 year-old male with a giant apical left ventricular pseudoaneurysm after an unnoticed myocardial infarction is presented. On coronary angiogram myocardial bridging of the distal left anterior descending artery was judged to be the infarct related lesion. The echocardiographic diagnosis allowed for a timely surgical intervention which resulted in the patient's full recovery.

Myocardial bridging in absence of coronary artery disease: proposal of a new classification based on clinical-angiographic data and long-term follow-up

BACKGROUND

There is no widely accepted classification to guide therapy in patients with symptomatic myocardial bridging (MB).

METHODS

A retrospective analysis of 157 patients with chest pain, angiographic MB of the left anterior descending artery without obstructive coronary artery disease (CAD) was performed. Patients were evaluated for clinical symptoms, objective signs of ischemia by stress test, intracoronary Doppler flow measurement and coronary flow reserve. 100 patients without CAD or MB served as controls.

RESULTS

There was no difference in clinical symptoms and objective signs of ischemia between controls and patients with MB. The length of MB was 22.6 +/- 7.8 mm, maximal systolic luminal diameter reduction 71 +/- 16%, and maximal mid-diastolic luminal reduction 34.7 +/- 13% as demonstrated by quantitative coronary angiography (QCA). Intracoronary Doppler showed significantly increased average peak flow velocity (APV), average systolic peak velocity (ASPV), average diastolic peak flow velocity (ADPV), and maximal peak velocity (MPV) in MB versus proximal and distal segments at rest and after maximal vasodilatation (p < 0.001 for all parameters). Coronary flow reserve was significantly higher proximally (2.9 +/- 0.9) compared with segments distal to the MB (2.0 +/- 0.6, p < 0.01). We propose a new MB classification for symptomatic patients with MB:Type A:incidental finding on angiography, no objective signs of ischemia; Type B: objective signs of ischemia, and Type C: with or without objective signs of ischemia and altered intracoronary hemodynamics (by QCA/CFR/intracoronary Doppler). 5-Year follow-up data based on this classification showed that types B and C responded well to beta-blockers or calcium channel antagonists. Patients with type C refractory to medical therapy were treated with stenting of the MB.

CONCLUSION

Patients with MB without CAD did not have a higher prevalence of chest pain or abnormal non-invasive stress tests compared to patients without CAD or MB. Intracoronary hemodynamic measurement is a novel approach that may be valuable in defining the functional significance of MB. We propose a classification of symptomatic patients with MB without CAD using non-invasive and invasive parameters to guide therapeutic choices.

Low utilisation of cardiovascular risk reducing therapy in patients with acute coronary syndromes and non-obstructive coronary artery disease

BACKGROUND

Between 6-25% of patients undergoing coronary angiography for acute coronary syndrome (ACS) have non-obstructive coronary artery disease (NOCAD).

METHODS

One-hundred and eighty patients presenting with an ACS who were taking part in a risk factor modification study and had undergone coronary angiography were examined. We compared baseline characteristics, medical treatment and 12-month outcome in patients with NOCAD (<50% lumen diameter stenosis at coronary angiography) and obstructive CAD (> or = 50% lumen diameter stenosis at coronary angiography).

RESULTS

There were 29 (16%) patients with NOCAD and 151 (84%) with obstructive CAD (CAD). Patients with NOCAD were significantly younger, more likely to be female, had higher mean total cholesterol and LDL levels, and fewer received cardiac rehabilitation, treatment with statins, aspirin, ACE inhibitors, beta-blockers or clopidogrel. Over the next 12-months, there was no mortality or myocardial infarction in the NOCAD group compared to 2% in the CAD group, but 14% with NOCAD were readmitted for a cardiovascular cause including 2 patients (7%) who underwent percutaneous coronary intervention (PCI).

CONCLUSIONS

Patients presenting with ACS and NOCAD may not have a completely benign prognosis, and preventative strategies and therapies such as statins in this group of patients appear to be under-utilised.

Myocardial bridging as evaluated by 16 row MDCT

PURPOSE

The purpose of this study is to find out the prevalence, appearance and clinical symptoms of myocardial bridging (MB) by MDCT coronary angiography (CTA).

MATERIALS AND METHODS

A total of 280 (50 females) consecutive patients followed with coronary artery disease or postoperative stent and bypass control, underwent CTA performed by 16-MDCT scanner between January 2006 and April 2006. Short axis multiplanar reformatted images were evaluated. MBs were classified as complete and incomplete bridges with respect to continuity of the myocardium over the tunneled segment of left anterior descending artery (LAD) in interventricular groove and the cut-off value is 1.3mm. Patients diagnosed with MB on CTA who had prior catheter angiography studies were re-evaluated for the presence of MB.

RESULTS

One hundred and twenty MBs [98 (81.6%) on LAD, 2 (1.6%) on diagonal branch, 11 (9.1%) on obtuse marginal, 4 (3.3%) on right coronary artery, 5 (4.1%) on ramus intermedius artery] were detected in 108 (38.5%) patients. Eighty-five (70.8%) of bridged segments in 79 (28.2%) patients were complete and the rest [35 (29.2%) in 34 (12.1%) patients] were incomplete. In 12 patients two MBs (either on different arteries or on the same artery) were detected. The length of bridged segments in patients with complete and incomplete MBs varied between 4-50.9mm (mean 18mm) and 4-37.3mm (mean 13.6mm), respectively, and the depth of myocardium over the artery ranged between 1-6.4mm (mean 2.3mm) and 1-1.2mm (mean 1mm), respectively. Thirty (27.7%) out of 108 patients, in whom MB was detected on CTA, were found to have correlative catheter angiography studies, retrospectively and MB was detected only in 4 (13.3%) out of 30 patients.

CONCLUSION

MDCT coronary angiography is a non-invasive, efficient method in the diagnosis of MB avoiding the procedural risks that catheter angiography carries. MDCT coronary angiography allows direct visualization of the bridge itself and may thus give the opportunity to differentiate between complete and incomplete myocardial bridges.

Size of coronary artery in a myocardial bridge compared with adjacent nontunneled left anterior descending coronary artery

Patients with myocardial bridging (MB) may experience myocardial ischemia. Coronary stenting was reported to serve as an effective interventional approach to improve symptoms in selected patients with MB, but is related to high risk of coronary perforation. The aim of this study is to investigate vessel area in the myocardial bridge segment in comparison to that of adjacent segments proximal and distal to MB using intravascular ultrasound. A total of 81 myocardial bridge segments, characterized by a half-moon-shaped echolucent zone surrounding the intramural artery, were found in 78 patients using intravascular ultrasound. The cross-sectional area within the external elastic membrane and minimum and maximum diameters in the myocardial bridge segment and adjacent reference vessel segments were measured. Diastolic cross-sectional area within the external elastic membrane in the myocardial bridge segment was significantly smaller than that in adjacent segments both proximal and distal to MB (5.48+/-2.59 vs 9.40+/-3.48 and 7.22+/-2.87 mm2, respectively, both p<0.001). Maximum vessel diameter in the myocardial bridge segment during diastole was also smaller than that in the segment distal to MB (2.74+/-0.61 vs 3.12+/-0.59 mm, p<0.001). In conclusion, our study showed that vessel area in the myocardial bridge segment was smaller than that in adjacent segments proximal and distal to MB.

The relationship of myocardial bridges to coronary artery dominance in the adult human heart

Myocardial bridging is recognized as an anatomical variation of the human coronary circulation in which an epicardial artery lies in the myocardium for part of its course. Thus, the vessel is 'bridged' by myocardium. The anterior interventricular branch of the left coronary artery has been reported as the most common site of myocardial bridges but other locations have been reported. The purpose of this study was to provide more definitive information on the vessels with myocardial bridges, the length and depth of the bridged segment, and the relationship between the presence of bridges and coronary dominance. Two hundred formalin-fixed human hearts were examined. Myocardial bridges were found in 69 (34.5%) of the hearts with a total of 81 bridges. One bridge was found in 59 of these hearts and multiple bridges were observed in ten (eight with double bridges and two with triple bridges). Bridges were most often found over the anterior interventricular artery (35 hearts). Bridges were also found over the diagonal branch of the left coronary artery (14), over the left marginal branch (five) and over the inferior interventricular branch of the left coronary artery (six). Bridges were also found over the right coronary artery (15 hearts), over the right marginal branch (four) and over the inferior interventricular branch of the right coronary artery (two). The presence of bridges appeared to be related to coronary dominance, especially in the left coronary circulation. Forty-six (66.6%) of the hearts with bridges were left dominant. Forty-two of these had bridges over the left coronary circulation and four over the right coronary circulation. Seventeen hearts (24.6%) were right dominant. Eleven of these had bridges over the right coronary circulation and six over the left coronary circulation. The remaining six hearts were co-dominant with four having bridges over the left coronary circulation and two over the right coronary circulation. The mean length of the bridges was 31 mm and the mean depth was 12 mm. The possible clinical implications of myocardial bridging may vary from protection against atherosclerosis to systolic vessel compression and resultant myocardial ischaemia.

Myocardial infarction in a young female with reninoma induced hypertension and myocardial bridging

We present a case of myocardial infarction in a young female with reninoma induced hypertension and myocardial bridging. Reninoma is a rare and curable cause of secondary hypertension. Currently developed multi-detector computed tomography (MDCT) has permitted better evaluation of myocardial infarction and myocardial bridging. Myocardial infarction associated with reninoma and myocardial bridging has not been reported, and we report this interesting case.

Myocardial bridging

Myocardial bridging, a congenital coronary anomaly, is a clinical condition with several possible manifestations, and its clinical relevance is debated. This article reviews current knowledge about the anatomy, pathophysiology, clinical relevance, and treatment of myocardial bridging. Myocardial bridging is present when a segment of a major epicardial coronary artery, the 'tunnelled artery', runs intramurally through the myocardium. With each systole, the coronary artery is compressed. Myocardial bridging has been associated with angina, arrhythmia, depressed left ventricular function, myocardial stunning, early death after cardiac transplantation, and sudden death. Evidence indicates that the intima beneath the bridge is protected from atherosclerosis, and the proximal segment is more susceptible to development of atherosclerotic lesions because of haemodynamic disturbances. New techniques (e.g. intravascular ultrasonography and intracoronary Doppler studies) have revealed new characteristics and pathophysiologic processes such as diastolic flow abnormalities. Medical treatment generally includes beta-blockers. Nitrates should be avoided because symptoms may worsen. Intracoronary stents and surgery have been attempted in selected patients. Additional research is needed to define patients in whom myocardial bridging is potentially pathologic, and randomized multicentre long-term follow-up studies are needed to assess the natural history, patient selection, and therapeutic approaches.